The level of trust and respect Héctor Rondón has engendered in the Astros was evident no more so than at Dodger Stadium late on Friday night, when manager A.J. Hinch summoned him to replace Justin Verlander with two outs in the eighth inning to get out Manny Machado with a runner on base.

It was exactly the type of high-leverage situation the Astros’ bullpen failed to lock down both last postseason and in early season matchups against the Indians and the Yankees. But since taking over the closer’s role two months ago for the since-jettisoned Ken Giles, Rondón has quietly provided Houston a steady presence in the ninth inning.

Yet for reasons out of his control, Rondón’s hold on his role is suddenly tenuous at best. If the expected happens and the newly activated Roberto Osuna supplants Rondón as the Astros’ closer, it would be the second time in three seasons a polarizing trade deadline acquisition cost Rondón the opportunity to finish...